Period 4 days late but BFN

Jordane
I have never had a period more than 1 day late and I've been having them 10 years.. I am now 4 days late but keep getting BFN, I don't feel my usual self in the run upto me period except for sore boobs, but I've had an increase in appetite and feel sick on and off throughout he day? 
Am I being paranoid or could it be possible I am testing too early? 
Thanks